US4267238A - Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer - Google Patents
Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer Download PDFInfo
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- US4267238A US4267238A US06/100,699 US10069979A US4267238A US 4267238 A US4267238 A US 4267238A US 10069979 A US10069979 A US 10069979A US 4267238 A US4267238 A US 4267238A
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- magnetic recording
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/72—Protective coatings, e.g. anti-static or antifriction
- G11B5/725—Protective coatings, e.g. anti-static or antifriction containing a lubricant, e.g. organic compounds
- G11B5/7253—Fluorocarbon lubricant
- G11B5/7257—Perfluoropolyether lubricant
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
- C10M2213/04—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions obtained from monomers containing carbon, hydrogen, halogen and oxygen
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
- C10M2213/06—Perfluoro polymers
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
- C10M2217/04—Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C10M2217/042—Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds between the nitrogen-containing monomer and an aldehyde or ketone
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
- C10M2217/04—Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C10M2217/043—Mannich bases
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/30—Refrigerators lubricants or compressors lubricants
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/32—Wires, ropes or cables lubricants
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/34—Lubricating-sealants
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/36—Release agents or mold release agents
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/38—Conveyors or chain belts
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/40—Generators or electric motors in oil or gas winning field
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/42—Flashing oils or marking oils
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/44—Super vacuum or supercritical use
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/50—Medical uses
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/90—Magnetic feature
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
- Y10T428/31544—Addition polymer is perhalogenated
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31786—Of polyester [e.g., alkyd, etc.]
Definitions
- rigid magnetic recording disks and flexible magnetic recording media such as tape employed totally different types of lubricants.
- the invention concerns the lubrication of flexible magnetic recording media such as tapes and cards.
- the first lubricants were fatty acids and esters such as carnauba wax. These were either added to the dispersion of the magnetizable particles and binder resin or coated over the finished recording surface.
- the fatty acid/ester lubricants were considered to be satisfactory at ordinary ambient conditions but were not reliable at high temperatures and relative humidity, e.g., 40° C and 80% relative humidity. Also, minor variations in the use of the lubricants, such as variations in coating weights, can destroy their utility.
- U.S. Pat. No. 3,490,946 suggests the use of fluorocarbon compounds as lubricants for flexible magnetic recording tapes, either applied as a surface layer or dispersed into the mixture of binder and magnetizable particles.
- U.S. Pat. No. 3,778,308 rollser et al.
- U.S. Pat. No. 3,919,719 provides further information concerning the use of fluorinated polymers disclosed in U.S. Pat. No. 3,778,308.
- U.S. Pat. No. 3,954,637 (Pardee et al.) prepares a surface lubricant for magnetic recording tape from a dispersion in trifluorotrichloroethane of (a) a copolymer of trifluoroethylene and vinyl chloride and (b) a telomer of tetrafluoroethylene. This is then filtered to remove undissolved polymeric solids to provide a solution from which the lubricant is applied, U.S. Pat. No. 4,096,079 (Pardee) concerns the lubrication of phonograph records without mentioning magnetic recording media. A phonograph record is coated with essentially the same solution as the coating solution of U.S. Pat. No. 3,954,637 except for omission of the chlorinated copolymer (a). The average molecular weight of the fraction of the telomer (b) after the filtering is between 400 and 900.
- the present invention concerns a magnetic recording medium comprising a flexible backing and a magnetizable layer which has a lubricating coating that reliably provides effective lubrication at 40° C. annd 80% relative humidity. Surprisingly great latitude in the weight or thickness of the lubricating coating can be tolerated without interfering with the novel achievement.
- That lubricating coating comprises a fluorinated telechelic polyether polymer having a backbone comprising -C a F 2a -O- units wherein a is an integer from 1 to 4, which backbone is terminated by at least one polar group such that ⁇ 2 /MW is at least 19 ⁇ 10 -4 Debye 2 -moles/g.
- "Telechelic" polymers have low molecular weight and known functional terminal groups.
- N o Avogadro's Number
- the fluorinated telechelic polyether polymer preferably has a number average molecular weight of at least 1000 and a Ferranti-Shirley viscosity (measured at 1640 sec -1 and 20° C.) of at least 20 centipoise.
- the number average molecular weight of fluorinated telechelic polyether polymers having more than one terminal polar group per polymer molecule is preferably somewhat higher as compared to telechelic polymers having only one terminal polar group. For example, where there are two terminal polar groups per polymer molecule, the number average molecular weight preferably exceeds 1500.
- Useful polar groups for the fluorinated telechelic polyethers include
- R is alkyl of 1 to 6 carbon atoms, aryl or alkaryl of 6 to 10 carbon atoms; ##STR1## wherein each of R' and R" is hydrogen, alkyl of 1 to 6 carbon atoms, benzyl, or --R"' OH where R"' is an alkylene group of 2 to 6 carbon atoms;
- the pKa of the telechelic polyether polymer is at least 1.0.
- Preferred fluorinated telechelic polymers have the backbone--[CF 2 CF 2 O] m --]CF 2 O]n--, where m is an integer from about 6 to 32 and n is an integer from about 12 to 52, as disclosed in U.S. Pat. Nos. 3,810,874 and 4,085,137, or the backbone --CF(CF 3 )CF 2 O-- n or --CF 2 CF(CF 3 )O-- n , where n is an integer from about 6 to 20, as disclosed in U.S. Pat. Nos. 3,250,808 and 3,699,145.
- fluorinated telechelic polyethers are readily produced to have number average molecular weights within the preferred range of 1000-5000 and Ferranti-Shirley viscosities (measured at 1640 -1 sec) within the preferred range of 20-2000 centipoise.
- the fluorinated telechelic polyether polymer may also contain --CF 2 --CF 2 -- units which increase the separation between the ether oxygens and tend to make it necessary to avoid number average molecular weights toward the high end of the preferred range of 1000-5000 mentioned above. Otherwise, the viscosity of the fluorinated telechelic polyether polymer might be too high to provide good lubrication.
- Superior lubrication has been attained by applying the fluorinated telechelic polyether polymer with a rotogravure coater from solutions or emulsions as dilute as 0.1% by weight, thus producing what is believed to be a coating weight of about 10 mg/m 2 .
- a coating weight is approximately of monomolecular thickness. There has been no testing to assure that a coating of that thickness could continue to provide effective lubrication for a period of years.
- the actual coating weights are so small as to be difficult to measure, but superior lubrication has been achieved at coating weights which are believed to be about 10 to 150 mg/m 2 .
- fluorinated telechelic polymer from a 0.4-0.8% solution or emulsion to provide coating weights of about 25-60 mg/m 2 . This should provide reasonable assurance of good lubricating properties under adverse environmental conditions for a number of years.
- the fluorinated telechelic polyether polymer should comprise at least 10% by weight of the blended lubricants.
- the coating weight of the blended lubricants is from 25 to 150 mg/m 2 .
- the backing member of each of the magnetic recording media of the following examples was a flexible biaxially-oriented polyethylene terephthalate film having a thickness with the approximate range of 15 micrometers.
- a preferred fluorinated telechelic polyether polymer of the invention is ##STR3## where m and n are each integers providing an average molecular weight of about 2000, and has a Ferranti-Shirley viscosity of 1440 cps.
- 0.3 g of this telechelic polyether was emulsified in 60 g of isopropyl alcohol, and the emulsion was applied with a rotogravure coater over the recording layer of a flexible magnetizable recording tape.
- the recording layer comprised fine acicular magnetizable iron oxide particles in a binder comprising crosslinked polyvinyl chloride copolymer and polyester polyurethane.
- the recording layer was specifically designed for helical-scan video recording except that it contained no lubricant.
- the coated tape was slit to one-half-inch (1.27-cm) widths and then loaded into videocassettes of the "VHS" and "Betamax” formats.
- Two videocassettes of the Betamax format and one of the VHS format were tested on videorecorders at 40° C. and 80% relative humidity through 500 cycles, at which point the tests were terminated. None of the tapes had failed. Current industry standards require 200 passes without failure.
- Both of the Betamax cassettes were further tested to 1000 cycles, again with no failures.
- One Betamax cassette was tested to 1500 cycles, and its tape did not fail.
- Betamax videocassette tapes were prepared which were identical to those of Example 1 except having twice and half the coating weight, respectively. Each also passed 500 cycles at 40° C. and 80% relative humidity without failure.
- the same fluorinated telechelic polymer was coated over the recording layer of each of several endless-loop, 8-track audio recording tapes, the recording layers of which comprised acicular iron oxide particles in nonmagnetizable binder. At least 5-fold improvement was noted in resistance to wear at ordinary room temperature and 50% relative humidity as compared to typical endless-loop, 8-track audio recording tapes now on the market.
- Betamax videocassette tapes were prepared which were identical to those of Example 1 except that one lubricating coating contained 2.5 parts by weight of butyl myristate and the other, 2 parts by weight of myristic acid per part of the telechelic polymer.
- one lubricating coating contained 2.5 parts by weight of butyl myristate and the other, 2 parts by weight of myristic acid per part of the telechelic polymer.
- the fluorinated polymers of Example 1-8 and Comparative Examples A and B had the following values ( ⁇ s being measured at 100 Hz, except Example 1 at 10,000 Hz and Example 8 at 1000 Hz):
Abstract
Flexible magnetic recording tape is lubricated by a thin coating of a fluorinated telechelic polyether polymer having at least one polar group such as --CONHCH2 CH2 OH, --COOCH3, --CH2 OH, and --COCF3. This is believed to provide for the first time reliably effective lubrication at 40° C. and 80% relative humidity.
Description
U.S. Application Ser. No. 1,446, filed Jan. 8, 1979 (Pedrotty) claims one or a stack of rigid magnetic recording disks coated with fluorinated polymer lubricants which are the same as those of the present invention. Applicant and Mr. Pedrotty made their inventions in the same laboratory, and applicant is advised that Mr. Pedrotty made his invention first. However, applicant made the present invention before he became aware of Mr. Pedrotty's invention.
Prior to these inventions, rigid magnetic recording disks and flexible magnetic recording media such as tape employed totally different types of lubricants.
The invention concerns the lubrication of flexible magnetic recording media such as tapes and cards.
It has been known since the advent of magnetic recording tapes that their recording surfaces should be lubricated to permit sliding contact with recording heads and to inhibit adjacent convolutions of wound tape from sticking to each other after prolonged storage. The first lubricants were fatty acids and esters such as carnauba wax. These were either added to the dispersion of the magnetizable particles and binder resin or coated over the finished recording surface. The fatty acid/ester lubricants were considered to be satisfactory at ordinary ambient conditions but were not reliable at high temperatures and relative humidity, e.g., 40° C and 80% relative humidity. Also, minor variations in the use of the lubricants, such as variations in coating weights, can destroy their utility.
Very early in the development of magnetic recording tape, it was suggested that silicones might provide better lubrication at high ambient temperatures and relative humidity. See U.S. Pat. No. 2,654,681 (Lueck). Because of their higher cost and questionable superiority, only about 25 percent of current flexible magnetic recording media employ silicone lubricants while about 70 percent have fatty acid/ester lubrication. A very small percentage of flexible magnetic recording media is lubricated with graphite, especially in endless-loop tape cartridges. See U.S. Pat. No. 2,804,401 (Cousino).
U.S. Pat. No. 3,490,946 (Wolff) suggests the use of fluorocarbon compounds as lubricants for flexible magnetic recording tapes, either applied as a surface layer or dispersed into the mixture of binder and magnetizable particles. U.S. Pat. No. 3,778,308 (Roller et al.) more specifically suggests perfluoroalkyl polyethers as lubricant coatings for magnetic recording media. U.S. Pat. No. 3,919,719 (Wright et al.) provides further information concerning the use of fluorinated polymers disclosed in U.S. Pat. No. 3,778,308.
U.S. Pat. No. 3,954,637 (Pardee et al.) prepares a surface lubricant for magnetic recording tape from a dispersion in trifluorotrichloroethane of (a) a copolymer of trifluoroethylene and vinyl chloride and (b) a telomer of tetrafluoroethylene. This is then filtered to remove undissolved polymeric solids to provide a solution from which the lubricant is applied, U.S. Pat. No. 4,096,079 (Pardee) concerns the lubrication of phonograph records without mentioning magnetic recording media. A phonograph record is coated with essentially the same solution as the coating solution of U.S. Pat. No. 3,954,637 except for omission of the chlorinated copolymer (a). The average molecular weight of the fraction of the telomer (b) after the filtering is between 400 and 900.
While it is believed that no magnetic recording tape now on the market employs a fluorinated lubricant, one manufacturer uses such a lubricant for the flexible magnetic recording disk of a diskette of the type shown in U.S. Pat. No. 3,668,658 (Flores et al.).
Highly fluorinated polyether polymers have been provided with terminal polar groups which can react with other polyfunctional molecules to form polyurethanes, polyesters, polysiloxanes, polyamides or the like as disclosed in U.S. Pat. Nos. 3,810,874 and 4,085,137 (Mitsch et al.). The latter at column 11, lines 42-49 teaches that said polymers containing terminal polar groups are also useful as lubricants, but without illustrating that use. U.S. Pat. No. 4,097,388 (Snyder et al.) uses the same fluorinated prepolymers, except with different terminal polar groups, as lubricants for engine oils, hydraulic fluids, and greases.
The present invention concerns a magnetic recording medium comprising a flexible backing and a magnetizable layer which has a lubricating coating that reliably provides effective lubrication at 40° C. annd 80% relative humidity. Surprisingly great latitude in the weight or thickness of the lubricating coating can be tolerated without interfering with the novel achievement. That lubricating coating comprises a fluorinated telechelic polyether polymer having a backbone comprising -Ca F2a -O- units wherein a is an integer from 1 to 4, which backbone is terminated by at least one polar group such that μ2 /MW is at least 19×10-4 Debye2 -moles/g. "Telechelic" polymers have low molecular weight and known functional terminal groups.
The dipole momemt μ of the fluorinated telechelic polymer can be calculated from the Onsager Relation ##EQU1## where k=Boltzmann's Constant
T=Temperature in °K
MW=Molecular Weight
No =Avogadro's Number
d=Density
εs =Dielectric constant measured at low frequencies,
ε.sub.∞ =Dielectric constant measured at high frequencies, where the approximation is made through Maxwell's Relations that
ε.sub.∞ =η.sub.D.sup.2 +(5-10%)η.sub.D.sup.2 ≃1.075 η.sub.D.sup.2
where ηD is the refractive index of the material at the sodium D line at 20° C. The fluorinated telechelic polyether polymer preferably has a number average molecular weight of at least 1000 and a Ferranti-Shirley viscosity (measured at 1640 sec-1 and 20° C.) of at least 20 centipoise. The number average molecular weight of fluorinated telechelic polyether polymers having more than one terminal polar group per polymer molecule is preferably somewhat higher as compared to telechelic polymers having only one terminal polar group. For example, where there are two terminal polar groups per polymer molecule, the number average molecular weight preferably exceeds 1500.
Useful polar groups for the fluorinated telechelic polyethers include
--CO2 R wherein R is alkyl of 1 to 6 carbon atoms, aryl or alkaryl of 6 to 10 carbon atoms; ##STR1## wherein each of R' and R" is hydrogen, alkyl of 1 to 6 carbon atoms, benzyl, or --R"' OH where R"' is an alkylene group of 2 to 6 carbon atoms;
--Cb H2b OH;
--Cb H2b NR'R"; ##STR2## --C(OH)2 Cb F2b+1 wherein b is an integer of 1 to 4. Strongly acidic polar groups such as carboxylic or sulfonic acid groups are less desirable because they are potentially corrosive. This may be minimized by conversion to salts. Preferably the pKa of the telechelic polyether polymer is at least 1.0.
Preferred fluorinated telechelic polymers have the backbone--[CF2 CF2 O]m --]CF2 O]n--, where m is an integer from about 6 to 32 and n is an integer from about 12 to 52, as disclosed in U.S. Pat. Nos. 3,810,874 and 4,085,137, or the backbone --CF(CF3)CF2 O--n or --CF2 CF(CF3)O--n, where n is an integer from about 6 to 20, as disclosed in U.S. Pat. Nos. 3,250,808 and 3,699,145.
Such fluorinated telechelic polyethers are readily produced to have number average molecular weights within the preferred range of 1000-5000 and Ferranti-Shirley viscosities (measured at 1640-1 sec) within the preferred range of 20-2000 centipoise. The fluorinated telechelic polyether polymer may also contain --CF2 --CF2 -- units which increase the separation between the ether oxygens and tend to make it necessary to avoid number average molecular weights toward the high end of the preferred range of 1000-5000 mentioned above. Otherwise, the viscosity of the fluorinated telechelic polyether polymer might be too high to provide good lubrication.
Superior lubrication has been attained by applying the fluorinated telechelic polyether polymer with a rotogravure coater from solutions or emulsions as dilute as 0.1% by weight, thus producing what is believed to be a coating weight of about 10 mg/m2. Such a coating is approximately of monomolecular thickness. There has been no testing to assure that a coating of that thickness could continue to provide effective lubrication for a period of years. The actual coating weights are so small as to be difficult to measure, but superior lubrication has been achieved at coating weights which are believed to be about 10 to 150 mg/m2. It is currently preferred to apply the fluorinated telechelic polymer from a 0.4-0.8% solution or emulsion to provide coating weights of about 25-60 mg/m2. This should provide reasonable assurance of good lubricating properties under adverse environmental conditions for a number of years.
It may be desirable to blend the fluorinated telechelic polyether polymer with other lubricants such as fatty acids and esters to provide reliable stop-motion in video tape recorders at high temperatures and high relative humidity. The fluorinated telechelic polyether polymer should comprise at least 10% by weight of the blended lubricants. Preferably the coating weight of the blended lubricants is from 25 to 150 mg/m2.
The backing member of each of the magnetic recording media of the following examples was a flexible biaxially-oriented polyethylene terephthalate film having a thickness with the approximate range of 15 micrometers.
A preferred fluorinated telechelic polyether polymer of the invention is ##STR3## where m and n are each integers providing an average molecular weight of about 2000, and has a Ferranti-Shirley viscosity of 1440 cps. 0.3 g of this telechelic polyether was emulsified in 60 g of isopropyl alcohol, and the emulsion was applied with a rotogravure coater over the recording layer of a flexible magnetizable recording tape. The recording layer comprised fine acicular magnetizable iron oxide particles in a binder comprising crosslinked polyvinyl chloride copolymer and polyester polyurethane. The recording layer was specifically designed for helical-scan video recording except that it contained no lubricant.
After the telechelic polymer coating was dried in an oven at about 50° C. to a dried coating weight of about 37.5 mg/m2, the coated tape was slit to one-half-inch (1.27-cm) widths and then loaded into videocassettes of the "VHS" and "Betamax" formats. Two videocassettes of the Betamax format and one of the VHS format were tested on videorecorders at 40° C. and 80% relative humidity through 500 cycles, at which point the tests were terminated. None of the tapes had failed. Current industry standards require 200 passes without failure. Both of the Betamax cassettes were further tested to 1000 cycles, again with no failures. One Betamax cassette was tested to 1500 cycles, and its tape did not fail.
Two Betamax videocassette tapes were prepared which were identical to those of Example 1 except having twice and half the coating weight, respectively. Each also passed 500 cycles at 40° C. and 80% relative humidity without failure.
The same fluorinated telechelic polymer was coated over the recording layer of each of several endless-loop, 8-track audio recording tapes, the recording layers of which comprised acicular iron oxide particles in nonmagnetizable binder. At least 5-fold improvement was noted in resistance to wear at ordinary room temperature and 50% relative humidity as compared to typical endless-loop, 8-track audio recording tapes now on the market.
Two Betamax videocassette tapes were prepared which were identical to those of Example 1 except that one lubricating coating contained 2.5 parts by weight of butyl myristate and the other, 2 parts by weight of myristic acid per part of the telechelic polymer. When tested at 40° C. and 80% relative humidity, the first tape passed 200 cycles and the second passed 500 cycles without failure, whereupon testing was discontinued.
The following telechelic fluorinated polyether polymers were tested as lubricants for the same magnetic recording tape as in Example 1 except that the test results are here reported only for Betamax videocassettes.
__________________________________________________________________________ Viscosity Example No.ave. (Fer-Sh) No. MW Cps. __________________________________________________________________________ ##STR4## 3500 54 3 HOCH.sub.2CF.sub.2 O(CF.sub.2 CF.sub.2 O).sub.m(CF.sub.2 O).sub.nCF .sub.2CH.sub.2 OH 2000 24 4 " 4000 194 5 ##STR5## 2600 125 6 ##STR6## 3200 1130 7 ##STR7## 3200 345 8 ##STR8## 3300 1785 Comparative Example No. A ##STR9## 3600 708 B ##STR10## 1300 77 __________________________________________________________________________
The fluorinated polymers of Example 1-8 and Comparative Examples A and B had the following values (εs being measured at 100 Hz, except Example 1 at 10,000 Hz and Example 8 at 1000 Hz):
______________________________________ μ.sup.2 /MW Example m n d ε.sub.s ε.sub.∞ × 104 ______________________________________ 1 8 14 1.772 23.0 1.876 809 2 16 28 1.750 2.86 1.805 53.7 3 8 14 1.793 2.80 1.809 49.4 4 16 28 1.814 2.55 1.805 37.6 5 -- 15 1.874 2.22 1.814 20.6 6 -- 18 1.80 2.36 1.825 27.6 7 -- 18 1.848 2.79 1.822 46.6 8 -- 18 1.90 3.68 1.843 80.2 A -- 20 1.886 2.14 1.816 16.7 B -- 10 1.860 2.15 1.797 18.2 ______________________________________
Each test of a tape of Examples 2-8 and Comparative Examples A and B was continued until failure or 500 cycles without failure at 40° C. and the indicated relative humidity. Each test was discontinued immediately after any failure such as jamming of the tape, visual scoring of its magnetizable layer, accumulations of visible residue on the video heads, a 6 dB loss in video signal, or sticking of the tape to the video capstan, audio stack or to any other surface. Results are summarized below:
______________________________________ Test Results Polymer Relative No. of Example Concentration Vehicle Humidity Passes ______________________________________ 2 1% IPA 85% 500+ 0.5% " " 452 3 1% " 80% 500+ (2 tapes) 0.25% Freon " 500+ 4 1% IPA 85% 119 " " " 30 " " " 500+ 5 " Freon 80% 500+ (2 tapes) " IPA " 500+ (2 tapes) 0.5% " " 71 6 " " " 500+ 7 1% " " " 0.5% " " " 8 1% " " 500+ " " " 40 0.5% " " 5 " " " 481 A 1% " " 124 " " 85% 15 0.5% " " 29 B 1% " 50%* 383 0.5% " 50%* 212 ______________________________________ *tested at 20° C. 500+ indicates no failure at 500 cycles IPA = isopropyl alcohol Freon = CClF.sub.2 CCl.sub.2 F sold as "Freon" 113
Claims (7)
1. Magnetic recording medium comprising a flexible backing and magnetizable layer, said layer having a lubricating coating comprising a fluorinated telechelic polyether polymer having a backbone comprising --Ca F2a --O--units wherein a is an integer from 1 to 4, which backbone is terminated by at least one polar group, the μ2 /MW of the polymer being at least 19×10-4 Debye2 -moles/g, which lubricating coating reliably provides effective lubrication at 40° C. and 80% relative humidity.
2. Magnetic recording medium as defined in claim 1, wherein at least one polar end group is selected from
--CO2 R wherein R is alkyl of 1 to 6 carbon atoms, aryl or alkaryl of 6 to 10 carbon atoms; ##STR11## wherein each of R' and R" is hydrogen, alkyl of 1 to 6 carbon atoms, benzyl, or --R"' OH where R"' is an alkylene group of 2 to 6 carbon atoms;
--Cb H2b OH;
--Cb H2b NR'R" ; ##STR12## --C(OH)2 Cb F2b+1 wherein b is an integer of 1 to 4.
3. Magnetic recording medium as defined in claim 2, wherein said telechelic polymer is selected from ##STR13## and m and n are each integers.
4. Magnetic recording medium as defined in claim 1, wherein the Ferranti-Shirley viscosity of said telechelic polymer is at least 20 centipoise.
5. Magnetic recording medium as defined in claim 4, wherein the Ferranti-Shirley viscosity of said telechelic polymer is at most 2000 centipoise.
6. Magnetic recording medium as defined in claim 1, wherein said telechelic polymer has a number average molecular weight of at least 1000.
7. Magnetic recording medium as defined in claim 1, wherein up to 90% by weight of said lubricating coating comprises a fatty acid or ester and has a coating weight of 25-150 mg/m2.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/100,699 US4267238A (en) | 1979-12-18 | 1979-12-18 | Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer |
NLAANVRAGE8000060,A NL189629C (en) | 1979-01-08 | 1980-01-04 | MAGNETIC RECORD MEDIA LUBRICATED WITH A FLUORATED POLYETHERPOLYMER. |
BR8000073A BR8000073A (en) | 1979-01-08 | 1980-01-07 | MAGNETIC RECORDING MEDIA |
GB8000389A GB2042369B (en) | 1979-01-08 | 1980-01-07 | Lubricating coatings for magnetic recording media |
FR8000201A FR2458867B1 (en) | 1979-01-08 | 1980-01-07 | LUBRICATION OF RECORDING MAGNETIC MATERIALS BY TELECHELIC FLUORINATED POLYMERS |
AU54383/80A AU524438B2 (en) | 1979-01-08 | 1980-01-07 | Lubricated magnetic recording media |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/100,699 US4267238A (en) | 1979-12-18 | 1979-12-18 | Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer |
Publications (1)
Publication Number | Publication Date |
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US4267238A true US4267238A (en) | 1981-05-12 |
Family
ID=22281091
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/100,699 Expired - Lifetime US4267238A (en) | 1979-01-08 | 1979-12-18 | Flexible magnetic recording media lubricated with fluorinated telechelic polyether polymer |
Country Status (1)
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US (1) | US4267238A (en) |
Cited By (48)
Publication number | Priority date | Publication date | Assignee | Title |
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US4404247A (en) * | 1982-07-02 | 1983-09-13 | Minnesota Mining And Manufacturing Company | Protective covering for magnetic recording medium |
US4419404A (en) * | 1981-02-16 | 1983-12-06 | Fuji Photo Film Co., Ltd. | Magnetic recording media and process of producing them |
US4431702A (en) * | 1981-04-27 | 1984-02-14 | Tdk Electronics Co., Ltd. | Magnetic recording medium |
US4477520A (en) * | 1979-12-24 | 1984-10-16 | Fujitsu Limited | Magnetic recording media having lubricated contact layer |
US4526836A (en) * | 1983-09-16 | 1985-07-02 | Victor Company Of Japan, Ltd. | Magnetic recording media comprising a reaction product of a specific type of fluorine resin and a curing polymer material as a binder in the magnetic layer thereof |
US4526833A (en) * | 1983-10-03 | 1985-07-02 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having a perfluoropolyether polymer protective coating |
US4529659A (en) * | 1983-11-05 | 1985-07-16 | Nippon Telegraph & Telephone Public Corporation | Magnetic recording member and process for manufacturing the same |
US4536444A (en) * | 1983-11-17 | 1985-08-20 | Hitachi Maxell, Ltd. | Magnetic recording medium |
US4546035A (en) * | 1983-06-27 | 1985-10-08 | International Business Machines Corporation | Polymeric additives for magnetic coating materials |
EP0165650A2 (en) * | 1984-06-19 | 1985-12-27 | AUSIMONT S.r.l. | Fluoropolyether compounds |
EP0165649A2 (en) * | 1984-06-19 | 1985-12-27 | Montedison S.p.A. | Fluoropolyether compounds |
DE3539380A1 (en) * | 1984-11-07 | 1986-05-07 | Hitachi, Ltd., Tokio/Tokyo | MAGNETIC RECORDING MATERIAL |
US4613548A (en) * | 1985-02-11 | 1986-09-23 | Ethyl Corporation | Polyphosphazene magnetic tape lube |
US4671999A (en) * | 1983-09-19 | 1987-06-09 | Minnesota Mining And Manufacturing Company | Magnetic recording media having perfluoropolyether coating |
US4689254A (en) * | 1984-02-01 | 1987-08-25 | Verbatim Corporation | Magnetic recording element having a lubricative and protective coating |
JPS62246621A (en) * | 1986-04-16 | 1987-10-27 | Yobea Rulon Kogyo Kk | Rolling bearing |
US4705699A (en) * | 1983-09-19 | 1987-11-10 | Minnesota Mining And Manufacturing Company | Method of coating magnetic recording media with perfluoropolyether compositions which are soluble in non-fluorinated solvents |
US4729924A (en) * | 1984-12-21 | 1988-03-08 | Minnesota Mining And Manufacturing Company | Metallic thin film magnetic recording medium having a hard protective layer |
US4803130A (en) * | 1984-12-21 | 1989-02-07 | Minnesota Mining And Manufacturing Company | Reactive sputtering process for recording media |
US4842939A (en) * | 1985-10-30 | 1989-06-27 | Scarati Mario A | Process for protecting and lubricating surfaces subjected to friction and wear |
US4849291A (en) * | 1987-12-02 | 1989-07-18 | Eastman Kodak Company | Magnetic recording element |
US4873138A (en) * | 1983-02-24 | 1989-10-10 | Fuji Photo Film Co., Ltd. | Metallic thin film type magnetic recording medium |
US4897211A (en) * | 1987-04-16 | 1990-01-30 | Hitachi Metals, Ltd. | Synthetic lubricant for lubricating thin film and magnetic recording medium |
US5071715A (en) * | 1986-02-04 | 1991-12-10 | Hitachi, Ltd. | Magnetic recording medium with a lubricant layer containing a perfluoro polyoxyalkyl compound |
US5091249A (en) * | 1989-07-11 | 1992-02-25 | Fuji Photo Film Co., Ltd. | Magnetic recording medium lubricant comprising two different fluorinated polyethers each having specified terminal groups |
US5120608A (en) * | 1989-09-02 | 1992-06-09 | Basf Aktiengesellschaft | Magnetic recording media comprising a polyurethane binder resin containing perfluoro groups |
US5169721A (en) * | 1989-09-02 | 1992-12-08 | Basf Aktiengesellschaft | Magnetic recording media comprising a polyurethane binder resin containing perfluoro groups |
US5178954A (en) * | 1989-07-21 | 1993-01-12 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having a metallic magnetic thin film layer, a primer layer comprising an amino alkoxysilane and a lubricant layer comprising a functional perfluoropolyether |
US5210188A (en) * | 1991-02-15 | 1993-05-11 | Ausimont S.P.A. | Dyestuffs for perfluoropolyoxyalkylenes and compositions based on perfluoropolyoxyalkylenes containing such dyestuffs |
US5223342A (en) * | 1986-02-04 | 1993-06-29 | Hitachi, Ltd. | Magnetic recording medium having a lubricating layer comprising a binder and specified perfluoro polyoxyalkyl lubricant |
US5268227A (en) * | 1989-07-14 | 1993-12-07 | Fuji Photo Film Co., Ltd. | Magnetic recording medium comprising a ferromagnetic metallic then film having a top coat of (a) a hydrocarbonsulfuric or hydrocarbonsulfonic acid or salt and (b) a fluorinated polyether |
US5306758A (en) * | 1989-12-14 | 1994-04-26 | Minnesota Mining And Manufacturing Company | Fluorocarbon-based coating compositions and articles derived therefrom |
US5382614A (en) * | 1986-03-27 | 1995-01-17 | Ausimont S.P.A. | Perfluoropolyether lubricants for magnetic recordings |
US5446205A (en) * | 1989-04-20 | 1995-08-29 | Ausimont S.R.L. | Functionalized fluoropolyethers |
US5498359A (en) * | 1993-02-24 | 1996-03-12 | Hitachi Maxell, Ltd. | Lubricant |
US5607782A (en) * | 1992-08-21 | 1997-03-04 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
US5679752A (en) * | 1995-03-15 | 1997-10-21 | Minnesota Mining And Manufacturing Company | Magnetic recording medium incorporating fluorine-containing, solvent-soluble vinyl copolymer having no vinyl chloride or vinylidene chloride components |
US5823455A (en) * | 1996-12-20 | 1998-10-20 | Imation Corp. | Belt-driven data storage device with corner roller assemblies preselected to have different drag force profiles |
US5908817A (en) * | 1998-05-18 | 1999-06-01 | The Dow Chemical Company | Lubricants containing a perfluoropolyalkyl ether and a fluoroalkylphosphazene |
US5909337A (en) * | 1997-08-12 | 1999-06-01 | International Business Machines Corporation | Magnetic recording device |
US5965496A (en) * | 1994-10-13 | 1999-10-12 | Daikin Industries, Ltd. | Fluorine-containing compounds and use thereof |
US6348266B1 (en) | 1998-09-22 | 2002-02-19 | Seagate Technology Llc | Amphiphillic lubricants for magnetic media |
US6468947B1 (en) | 1999-03-26 | 2002-10-22 | Seagate Technology Llc | Lubricants with improved stability for magnetic recording media |
US20030094698A1 (en) * | 1999-11-10 | 2003-05-22 | Matsushita Electronics Corporation | Semiconductor device and method for fabricating the same |
US20050076650A1 (en) * | 2003-10-08 | 2005-04-14 | Rodolphe Dudebout | Auxiliary power unit having a rotary fuel slinger |
US20050090408A1 (en) * | 2003-10-24 | 2005-04-28 | Burns John M. | Solubility of perfluorinated polyethers in fluorinated solvents |
US20050209468A1 (en) * | 2004-03-16 | 2005-09-22 | Burns John M | Method for liquid/liquid extraction of molecular weight fractions of perfluorinated polyethers |
US20090291325A1 (en) * | 2006-07-13 | 2009-11-26 | Agency For Science, Technology And Research | Phosphazene Compound, Lubricant and Magentic Recording Medium Having Such Compound, Method of Preparation, and Method of Lubrication |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2654681A (en) * | 1950-01-27 | 1953-10-06 | Minnesota Mining & Mfg | Magnetic recording tape |
US2804401A (en) * | 1955-04-11 | 1957-08-27 | Bernard A Cousino | Magnetic sound tape |
US3250808A (en) * | 1963-10-31 | 1966-05-10 | Du Pont | Fluorocarbon ethers derived from hexafluoropropylene epoxide |
US3490946A (en) * | 1966-12-29 | 1970-01-20 | Rca Corp | Magnetic recording elements |
US3668658A (en) * | 1969-12-22 | 1972-06-06 | Ibm | Magnetic record disk cover |
US3699145A (en) * | 1964-04-09 | 1972-10-17 | Montedison Spa | Fluorinated oxygen-containing products and process for preparation thereof |
US3778308A (en) * | 1970-12-18 | 1973-12-11 | Ball Brothers Res Corp | Magnetic storage device coating and process |
US3810874A (en) * | 1969-03-10 | 1974-05-14 | Minnesota Mining & Mfg | Polymers prepared from poly(perfluoro-alkylene oxide) compounds |
US3919719A (en) * | 1974-04-04 | 1975-11-11 | Iit Res Inst | Surface lubrication of magnetic media |
US3954637A (en) * | 1973-06-25 | 1976-05-04 | Ball Brothers Research Corporation | Method and composition for lubricating and lubricated substrates |
US3973072A (en) * | 1973-02-20 | 1976-08-03 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having binder-free phosphide coating |
US4012551A (en) * | 1974-02-05 | 1977-03-15 | Warner-Lambert Company | Coated razor blade |
US4085137A (en) * | 1969-03-10 | 1978-04-18 | Minnesota Mining And Manufacturing Company | Poly(perfluoroalkylene oxide) derivatives |
US4096079A (en) * | 1976-09-10 | 1978-06-20 | Ball Brothers Research Corporation | Protective lubricating compositions for recordings |
US4097388A (en) * | 1976-10-12 | 1978-06-27 | The United States Of America As Represented By The Secretary Of The Air Force | Linear fluorinated polyether lubricant compositions containing perfluoroalkylether substituted phosphines |
-
1979
- 1979-12-18 US US06/100,699 patent/US4267238A/en not_active Expired - Lifetime
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2654681A (en) * | 1950-01-27 | 1953-10-06 | Minnesota Mining & Mfg | Magnetic recording tape |
US2804401A (en) * | 1955-04-11 | 1957-08-27 | Bernard A Cousino | Magnetic sound tape |
US3250808A (en) * | 1963-10-31 | 1966-05-10 | Du Pont | Fluorocarbon ethers derived from hexafluoropropylene epoxide |
US3699145A (en) * | 1964-04-09 | 1972-10-17 | Montedison Spa | Fluorinated oxygen-containing products and process for preparation thereof |
US3490946A (en) * | 1966-12-29 | 1970-01-20 | Rca Corp | Magnetic recording elements |
US3810874A (en) * | 1969-03-10 | 1974-05-14 | Minnesota Mining & Mfg | Polymers prepared from poly(perfluoro-alkylene oxide) compounds |
US4085137A (en) * | 1969-03-10 | 1978-04-18 | Minnesota Mining And Manufacturing Company | Poly(perfluoroalkylene oxide) derivatives |
US3668658A (en) * | 1969-12-22 | 1972-06-06 | Ibm | Magnetic record disk cover |
US3778308A (en) * | 1970-12-18 | 1973-12-11 | Ball Brothers Res Corp | Magnetic storage device coating and process |
US3778308B1 (en) * | 1970-12-18 | 1991-06-04 | Magnetic storage device coating and process | |
US3973072A (en) * | 1973-02-20 | 1976-08-03 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having binder-free phosphide coating |
US3954637A (en) * | 1973-06-25 | 1976-05-04 | Ball Brothers Research Corporation | Method and composition for lubricating and lubricated substrates |
US4012551A (en) * | 1974-02-05 | 1977-03-15 | Warner-Lambert Company | Coated razor blade |
US3919719A (en) * | 1974-04-04 | 1975-11-11 | Iit Res Inst | Surface lubrication of magnetic media |
US4096079A (en) * | 1976-09-10 | 1978-06-20 | Ball Brothers Research Corporation | Protective lubricating compositions for recordings |
US4097388A (en) * | 1976-10-12 | 1978-06-27 | The United States Of America As Represented By The Secretary Of The Air Force | Linear fluorinated polyether lubricant compositions containing perfluoroalkylether substituted phosphines |
Cited By (63)
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US4477520A (en) * | 1979-12-24 | 1984-10-16 | Fujitsu Limited | Magnetic recording media having lubricated contact layer |
US4419404A (en) * | 1981-02-16 | 1983-12-06 | Fuji Photo Film Co., Ltd. | Magnetic recording media and process of producing them |
US4551778A (en) * | 1981-02-16 | 1985-11-05 | Fuji Photo Film Co., Ltd. | Magnetic recording media and process of producing them |
US4431702A (en) * | 1981-04-27 | 1984-02-14 | Tdk Electronics Co., Ltd. | Magnetic recording medium |
US4404247A (en) * | 1982-07-02 | 1983-09-13 | Minnesota Mining And Manufacturing Company | Protective covering for magnetic recording medium |
US4873138A (en) * | 1983-02-24 | 1989-10-10 | Fuji Photo Film Co., Ltd. | Metallic thin film type magnetic recording medium |
US4546035A (en) * | 1983-06-27 | 1985-10-08 | International Business Machines Corporation | Polymeric additives for magnetic coating materials |
US4526836A (en) * | 1983-09-16 | 1985-07-02 | Victor Company Of Japan, Ltd. | Magnetic recording media comprising a reaction product of a specific type of fluorine resin and a curing polymer material as a binder in the magnetic layer thereof |
US4705699A (en) * | 1983-09-19 | 1987-11-10 | Minnesota Mining And Manufacturing Company | Method of coating magnetic recording media with perfluoropolyether compositions which are soluble in non-fluorinated solvents |
US4671999A (en) * | 1983-09-19 | 1987-06-09 | Minnesota Mining And Manufacturing Company | Magnetic recording media having perfluoropolyether coating |
US4526833A (en) * | 1983-10-03 | 1985-07-02 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having a perfluoropolyether polymer protective coating |
US4529659A (en) * | 1983-11-05 | 1985-07-16 | Nippon Telegraph & Telephone Public Corporation | Magnetic recording member and process for manufacturing the same |
US4536444A (en) * | 1983-11-17 | 1985-08-20 | Hitachi Maxell, Ltd. | Magnetic recording medium |
US4689254A (en) * | 1984-02-01 | 1987-08-25 | Verbatim Corporation | Magnetic recording element having a lubricative and protective coating |
EP0165649A2 (en) * | 1984-06-19 | 1985-12-27 | Montedison S.p.A. | Fluoropolyether compounds |
EP0165649A3 (en) * | 1984-06-19 | 1986-02-12 | Montedison S.P.A. | Fluoropolyether compounds |
EP0165650A3 (en) * | 1984-06-19 | 1986-02-19 | Montedison S.P.A. | Fluoropolyether compounds |
EP0165650A2 (en) * | 1984-06-19 | 1985-12-27 | AUSIMONT S.r.l. | Fluoropolyether compounds |
AU581640B2 (en) * | 1984-06-19 | 1989-03-02 | Montedison S.P.A. | Fluoropolyethers containing end groups endowed with anchoring capacity |
AU580749B2 (en) * | 1984-06-19 | 1989-02-02 | Montedison S.P.A. | Fluoropolyethers containing end groups endowed with anchoring capacity |
US4721795A (en) * | 1984-06-19 | 1988-01-26 | Montedison S.P.A. | Fluoropolyethers containing end groups endowed with anchoring capacity |
US4808472A (en) * | 1984-06-19 | 1989-02-28 | Montedison S.P.A. | Fluoropolyethers containing end groups endowed with anchoring capacity |
DE3539380A1 (en) * | 1984-11-07 | 1986-05-07 | Hitachi, Ltd., Tokio/Tokyo | MAGNETIC RECORDING MATERIAL |
US4803130A (en) * | 1984-12-21 | 1989-02-07 | Minnesota Mining And Manufacturing Company | Reactive sputtering process for recording media |
US4729924A (en) * | 1984-12-21 | 1988-03-08 | Minnesota Mining And Manufacturing Company | Metallic thin film magnetic recording medium having a hard protective layer |
US4613548A (en) * | 1985-02-11 | 1986-09-23 | Ethyl Corporation | Polyphosphazene magnetic tape lube |
US4842939A (en) * | 1985-10-30 | 1989-06-27 | Scarati Mario A | Process for protecting and lubricating surfaces subjected to friction and wear |
US5071715A (en) * | 1986-02-04 | 1991-12-10 | Hitachi, Ltd. | Magnetic recording medium with a lubricant layer containing a perfluoro polyoxyalkyl compound |
US5223342A (en) * | 1986-02-04 | 1993-06-29 | Hitachi, Ltd. | Magnetic recording medium having a lubricating layer comprising a binder and specified perfluoro polyoxyalkyl lubricant |
US5382614A (en) * | 1986-03-27 | 1995-01-17 | Ausimont S.P.A. | Perfluoropolyether lubricants for magnetic recordings |
JPS62246621A (en) * | 1986-04-16 | 1987-10-27 | Yobea Rulon Kogyo Kk | Rolling bearing |
US4897211A (en) * | 1987-04-16 | 1990-01-30 | Hitachi Metals, Ltd. | Synthetic lubricant for lubricating thin film and magnetic recording medium |
US4912252A (en) * | 1987-04-16 | 1990-03-27 | Hitachi Metals, Ltd. | Synthetic lubricant for lubricating thin film and magnetic recording medium |
US4849291A (en) * | 1987-12-02 | 1989-07-18 | Eastman Kodak Company | Magnetic recording element |
US5714637A (en) * | 1989-04-20 | 1998-02-03 | Ausimont S.R.L. | Functionalized fluoropolyethers |
US6156937A (en) * | 1989-04-20 | 2000-12-05 | Ausimont S.P.A. | Functionalized fluoropolyethers |
US5446205A (en) * | 1989-04-20 | 1995-08-29 | Ausimont S.R.L. | Functionalized fluoropolyethers |
US5091249A (en) * | 1989-07-11 | 1992-02-25 | Fuji Photo Film Co., Ltd. | Magnetic recording medium lubricant comprising two different fluorinated polyethers each having specified terminal groups |
US5268227A (en) * | 1989-07-14 | 1993-12-07 | Fuji Photo Film Co., Ltd. | Magnetic recording medium comprising a ferromagnetic metallic then film having a top coat of (a) a hydrocarbonsulfuric or hydrocarbonsulfonic acid or salt and (b) a fluorinated polyether |
US5178954A (en) * | 1989-07-21 | 1993-01-12 | Minnesota Mining And Manufacturing Company | Magnetic recording medium having a metallic magnetic thin film layer, a primer layer comprising an amino alkoxysilane and a lubricant layer comprising a functional perfluoropolyether |
US5120608A (en) * | 1989-09-02 | 1992-06-09 | Basf Aktiengesellschaft | Magnetic recording media comprising a polyurethane binder resin containing perfluoro groups |
US5169721A (en) * | 1989-09-02 | 1992-12-08 | Basf Aktiengesellschaft | Magnetic recording media comprising a polyurethane binder resin containing perfluoro groups |
US5306758A (en) * | 1989-12-14 | 1994-04-26 | Minnesota Mining And Manufacturing Company | Fluorocarbon-based coating compositions and articles derived therefrom |
US5210188A (en) * | 1991-02-15 | 1993-05-11 | Ausimont S.P.A. | Dyestuffs for perfluoropolyoxyalkylenes and compositions based on perfluoropolyoxyalkylenes containing such dyestuffs |
US5607782A (en) * | 1992-08-21 | 1997-03-04 | Fuji Photo Film Co., Ltd. | Magnetic recording medium |
US5498359A (en) * | 1993-02-24 | 1996-03-12 | Hitachi Maxell, Ltd. | Lubricant |
US5965496A (en) * | 1994-10-13 | 1999-10-12 | Daikin Industries, Ltd. | Fluorine-containing compounds and use thereof |
US5679752A (en) * | 1995-03-15 | 1997-10-21 | Minnesota Mining And Manufacturing Company | Magnetic recording medium incorporating fluorine-containing, solvent-soluble vinyl copolymer having no vinyl chloride or vinylidene chloride components |
US6265060B1 (en) | 1995-03-15 | 2001-07-24 | Imation Corp. | Magnetic recording medium incorporating fluorine-containing, solvent-soluble vinyl copolymer having no vinyl chloride or vinylidene chloride components |
US5823455A (en) * | 1996-12-20 | 1998-10-20 | Imation Corp. | Belt-driven data storage device with corner roller assemblies preselected to have different drag force profiles |
US5909337A (en) * | 1997-08-12 | 1999-06-01 | International Business Machines Corporation | Magnetic recording device |
US5908817A (en) * | 1998-05-18 | 1999-06-01 | The Dow Chemical Company | Lubricants containing a perfluoropolyalkyl ether and a fluoroalkylphosphazene |
US6660886B1 (en) | 1998-09-22 | 2003-12-09 | Seagate Technology Llc | Amphiphilic lubricants for magnetic media |
US6348266B1 (en) | 1998-09-22 | 2002-02-19 | Seagate Technology Llc | Amphiphillic lubricants for magnetic media |
US6468947B1 (en) | 1999-03-26 | 2002-10-22 | Seagate Technology Llc | Lubricants with improved stability for magnetic recording media |
US6703711B2 (en) * | 1999-11-10 | 2004-03-09 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device and method for fabricating the same |
US20030094698A1 (en) * | 1999-11-10 | 2003-05-22 | Matsushita Electronics Corporation | Semiconductor device and method for fabricating the same |
US20050076650A1 (en) * | 2003-10-08 | 2005-04-14 | Rodolphe Dudebout | Auxiliary power unit having a rotary fuel slinger |
US20050090408A1 (en) * | 2003-10-24 | 2005-04-28 | Burns John M. | Solubility of perfluorinated polyethers in fluorinated solvents |
US7247605B2 (en) | 2003-10-24 | 2007-07-24 | Hitachi Global Storage Technologies Netherlands B.V. | Solubility of perfluorinated polyethers in fluorinated solvents |
US20050209468A1 (en) * | 2004-03-16 | 2005-09-22 | Burns John M | Method for liquid/liquid extraction of molecular weight fractions of perfluorinated polyethers |
US7038068B2 (en) | 2004-03-16 | 2006-05-02 | Hitachi Global Storage Technologies Netherlands B.V. | Method for liquid/liquid extraction of molecular weight fractions of perfluorinated polyethers |
US20090291325A1 (en) * | 2006-07-13 | 2009-11-26 | Agency For Science, Technology And Research | Phosphazene Compound, Lubricant and Magentic Recording Medium Having Such Compound, Method of Preparation, and Method of Lubrication |
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